This invention concerns a semiconductor integrated circuit with an error correction function incorporated therein, particularly an integrated circuit that can determine whether or not the built-in error correction circuit has operated or not.
One method to increase the production yield of semiconductor integrated circuits is to repair defective devices by incorporating an error correction function. Simply incorporating an error correction function is sufficient if the only objective is to increase production yield, but in order to determine the influence the error correction function has on yield and on the electrical characteristics of the device, it must be differentiated whether the device was of good quality from the start, or it is working normally due to the functioning of an error correction function. Acquiring this type of data will simplify the management of the integrated circuit production process and help to increase product yield.
However, with present integrated circuits, the error correction function operates when necessary, and it is usually not possible to detect whether the device has been converted into one of normal quality by the incorporation of a error correction function in a defective device, thus making adequate quality control difficult.